import { QxReject, canonicalJson, type Json } from "@quixos/camino-replica-core";

export function boundedText(value: string, limit = 65536, allowEmpty = true): string {
  if (typeof value !== "string" || (!allowEmpty && !value.trim()) || new TextEncoder().encode(value).length > limit)
    throw new QxReject("AGENT_INVALID_TEXT");
  return value;
}
export function json(value: string, limit = 65536): Json {
  boundedText(value, limit, false);
  let parsed: Json;
  try {
    parsed = JSON.parse(value);
  } catch {
    throw new QxReject("AGENT_INVALID_JSON");
  }
  let nodes = 0;
  function walk(v: Json, depth: number) {
    if (++nodes > 8192 || depth > 24) throw new QxReject("AGENT_JSON_LIMIT");
    if (Array.isArray(v)) for (const child of v) walk(child, depth + 1);
    else if (v && typeof v === "object") for (const child of Object.values(v)) walk(child, depth + 1);
  }
  walk(parsed, 0);
  return parsed;
}
export function object(v: Json): Record<string, Json> {
  if (!v || Array.isArray(v) || typeof v !== "object") throw new QxReject("AGENT_EXPECTED_OBJECT");
  return v as Record<string, Json>;
}
export function timestamp(v: string) {
  if (!/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/.test(v) || !Number.isFinite(Date.parse(v)))
    throw new QxReject("AGENT_INVALID_TIME");
}
const schemaKeys = new Set([
  "type",
  "properties",
  "required",
  "items",
  "enum",
  "additionalProperties",
  "minimum",
  "maximum",
  "minLength",
  "maxLength",
  "minItems",
  "maxItems",
  "description",
  "title",
]);
export function schema(v: Json, depth = 0, budget = { nodes: 0 }): void {
  if (++budget.nodes > 256 || depth > 12) throw new QxReject("AGENT_SCHEMA_LIMIT");
  const s = object(v);
  for (const k of Object.keys(s)) if (!schemaKeys.has(k)) throw new QxReject("AGENT_SCHEMA_UNSUPPORTED");
  if (!["string", "number", "integer", "boolean", "null", "array", "object"].includes(String(s.type)))
    throw new QxReject("AGENT_SCHEMA_TYPE");
  if (s.enum !== undefined && (!Array.isArray(s.enum) || !s.enum.length || s.enum.length > 128))
    throw new QxReject("AGENT_SCHEMA_ENUM");
  for (const k of ["minimum", "maximum", "minLength", "maxLength", "minItems", "maxItems"]) {
    if (s[k] !== undefined && (typeof s[k] !== "number" || !Number.isFinite(s[k])))
      throw new QxReject("AGENT_SCHEMA_BOUND");
    if (
      k !== "minimum" &&
      k !== "maximum" &&
      s[k] !== undefined &&
      (Number(s[k]) < 0 || !Number.isInteger(s[k]) || Number(s[k]) > 65536)
    )
      throw new QxReject("AGENT_SCHEMA_BOUND");
  }
  for (const [min, max] of [
    ["minimum", "maximum"],
    ["minLength", "maxLength"],
    ["minItems", "maxItems"],
  ])
    if (s[min] !== undefined && s[max] !== undefined && Number(s[min]) > Number(s[max]))
      throw new QxReject("AGENT_SCHEMA_BOUND");
  if (s.type === "object") {
    const p = object(s.properties ?? {});
    if (Object.keys(p).length > 64) throw new QxReject("AGENT_SCHEMA_LIMIT");
    if (s.additionalProperties !== undefined && typeof s.additionalProperties !== "boolean")
      throw new QxReject("AGENT_SCHEMA_UNSUPPORTED");
    if (
      s.required !== undefined &&
      (!Array.isArray(s.required) ||
        s.required.some((k) => typeof k !== "string" || !Object.hasOwn(p, k)) ||
        new Set(s.required).size !== s.required.length)
    )
      throw new QxReject("AGENT_SCHEMA_REQUIRED");
    for (const child of Object.values(p)) schema(child, depth + 1, budget);
  }
  if (s.type === "array") schema(s.items ?? null, depth + 1, budget);
}
export function validateResult(supplied: Json, value: Json): void {
  schema(supplied);
  let nodes = 0;
  function check(shape: Json, v: Json, depth: number) {
    if (++nodes > 8192 || depth > 24) throw new QxReject("AGENT_RESULT_LIMIT");
    const s = object(shape),
      type = s.type;
    const actual = v === null ? "null" : Array.isArray(v) ? "array" : typeof v;
    if (!(type === actual || (type === "integer" && typeof v === "number" && Number.isInteger(v))))
      throw new QxReject("AGENT_RESULT_TYPE");
    if (s.enum && !(s.enum as Json[]).some((e) => canonicalJson(e) === canonicalJson(v)))
      throw new QxReject("AGENT_RESULT_ENUM");
    if (
      typeof v === "number" &&
      ((s.minimum !== undefined && v < Number(s.minimum)) || (s.maximum !== undefined && v > Number(s.maximum)))
    )
      throw new QxReject("AGENT_RESULT_BOUND");
    if (typeof v === "string") {
      const n = Array.from(v).length;
      if (n < Number(s.minLength ?? 0) || n > Number(s.maxLength ?? 65536)) throw new QxReject("AGENT_RESULT_BOUND");
    }
    if (Array.isArray(v)) {
      if (v.length < Number(s.minItems ?? 0) || v.length > Number(s.maxItems ?? 8192))
        throw new QxReject("AGENT_RESULT_BOUND");
      for (const e of v) check(s.items, e, depth + 1);
    }
    if (type === "object") {
      const p = object(s.properties ?? {}),
        o = object(v);
      for (const k of (s.required ?? []) as string[])
        if (!Object.hasOwn(o, k)) throw new QxReject("AGENT_RESULT_REQUIRED");
      for (const [k, e] of Object.entries(o)) {
        if (Object.hasOwn(p, k)) check(p[k], e, depth + 1);
        else if (s.additionalProperties === false) throw new QxReject("AGENT_RESULT_PROPERTY");
      }
    }
  }
  check(supplied, value, 0);
}
export function settings(value: string): Record<string, Json> {
  const s = object(json(value));
  const keys = new Set([
    "profile",
    "response",
    "capabilities",
    "notifications",
    "retry",
    "limits",
    "interactive",
    "systemInstructions",
  ]);
  for (const k of Object.keys(s)) if (!keys.has(k)) throw new QxReject("AGENT_SETTINGS_UNKNOWN");
  if (s.systemInstructions !== undefined) boundedText(s.systemInstructions as string);
  if (s.profile !== undefined) {
    if (typeof s.profile !== "string") throw new QxReject("AGENT_SETTINGS_TYPE");
    boundedText(s.profile, 80, false);
  }
  const response = object(s.response ?? { kind: "text" });
  for (const k of Object.keys(response))
    if (!["kind", "schema"].includes(k)) throw new QxReject("AGENT_RESPONSE_UNKNOWN");
  if (response.kind !== "json" && response.schema !== undefined) throw new QxReject("AGENT_UNEXPECTED_SCHEMA");
  if (!["text", "json", "unit"].includes(String(response.kind))) throw new QxReject("AGENT_RESPONSE_MODE");
  if (response.kind === "json") schema(response.schema ?? null);
  if (
    s.capabilities !== undefined &&
    (!Array.isArray(s.capabilities) ||
      s.capabilities.length > 6 ||
      new Set(s.capabilities).size !== s.capabilities.length ||
      s.capabilities.some(
        (c) => !["web-search", "graph-read", "graph-write", "eval", "source-read", "source-write"].includes(String(c)),
      ))
  )
    throw new QxReject("AGENT_CAPABILITY");
  if (s.retry !== undefined && !["never", "inference-only"].includes(String(s.retry)))
    throw new QxReject("AGENT_RETRY");
  if (
    s.retry === "inference-only" &&
    Array.isArray(s.capabilities) &&
    s.capabilities.some((c) => ["graph-write", "eval", "source-write"].includes(String(c)))
  )
    throw new QxReject("AGENT_UNSAFE_RETRY");
  for (const k of ["interactive", "notifications"])
    if (s[k] !== undefined && typeof s[k] !== "boolean") throw new QxReject("AGENT_SETTINGS_TYPE");
  if (s.limits !== undefined) {
    const limits = object(s.limits);
    for (const [k, v] of Object.entries(limits))
      if (
        !Object.hasOwn({ toolSteps: 128, activeMs: 1800000, outputBytes: 262144, retries: 1 }, k) ||
        !Number.isInteger(v) ||
        Number(v) < 0 ||
        Number(v) >
          ({ toolSteps: 128, activeMs: 1800000, outputBytes: 262144, retries: 1 } as Record<string, number>)[k]
      )
        throw new QxReject("AGENT_LIMIT");
  }
  return {
    profile: "balanced",
    response: { kind: "text" },
    capabilities: [],
    notifications: false,
    retry: "never",
    interactive: false,
    ...s,
  };
}